I'm looking for an easy way to lightweight way to debug RESTful services. For example, most webapps can be debugged using your average web browser. Unfortunately that same browser won't allow me to test HTTP PUT, DELETE, and to a certain degree even HTTP POST.
I am not looking to automate tests. I'd like to run new services through a quick sanity check, ideally without having to writing my own client.
Use an existing 'REST client' tool that makes it easy to inspect the requests and responses, like RESTClient or HTTP4E.
Aside from using one of the tools in Peter Hilton's response, I would have to say that scripting the tests with LWP or some similar tool may be your only option. You could bypass the use of LWP by just opening a socket, sending a raw HTTP request in and examining what you get in return. But as far as I know, there are a dearth of testing tools for this sort of domain-- most look at this problem-space primarily from the lens of a web-site developer, and for them the browser is enough of a testing platform.
I use restclient, available from Google Code. It's a simple Java Swing application which supports all HTTP methods, and allows you full control over the HTTP headers, conneg, etc.
I tend to write unit tests for RESTful resources using Jersey which comes with a nice REST client. The nice thing is if you implement your RESTful resources using JAX-RS then the Jersey client can reuse the entity providers such as for JAXB/XML/JSON/Atom and so forth - so you can reuse the same objects on the server side as you use on the client side unit test.
For example here is a unit test case from the Apache Camel project which looks up XML payloads from a RESTful resource (using the JAXB object Endpoints). The resource(uri) method is defined in this base class which just uses the Jersey client API.
e.g.
clientConfig = new DefaultClientConfig();
client = Client.create(clientConfig);
resource = client.resource("http://localhost:8080");
// lets get the XML as a String
String text = resource("foo").accept("application/xml").get(String.class);
At my firm we use a variety of different tools and approaches to testing RESTful services:
We write cURL scripts - essentially a single command saved in a file. One file per resource per method. For PUT and POST, we'll usually have files containing the representations to send alongside the cURL script. For example, for a mailbox resource, we might have a file named mailbox_post.cmd, which might contain the line curl -v -X POST -u username -H 'Content-Type:application/xml' -d @mailbox_post.xml http://service/mailbox. We like this approach because we end up building a collection of tests which can be run in a batch, or at least passed around between testers, and used for regression testing.
We use cURL and RESTClient for ad-hoc tests
We have the service serve XHTML by default, so it's browsable, and add forms resources, so the service is actually partially or fully testable using a browser. This was partly inspired by some parts of RESTful Web Services, wherein the authors show that the line between web services and web applications may not need to be as solid and strict as is usually assumed.
We write functional tests as Groovy closures, using the Restlet framework, and run the tests with a test runner Groovy script. This is useful because the tests can be stateful, build on each other, and share variables, when appropriate. We find Restlet's API to be simple and intuitive, and so easy to write quick HTTP requests and test the responses, and it's even easier when used in Groovy. (I hope to share this technique, including the test runner script, on our blog soon.)
A tool I've found useful if you're running OS X Leopard:
It's a very simple GUI program that allows you to craft http requests to a resource and view the response.
If you want free tool for the same purpose with additional feature of multipart form data submission it is here http://code.google.com/a/eclipselabs.org/p/restclient-tool/